Mario and Luigi were born in 1981. Kamek the Magikoopa who was the true evil mastermind behind Bowser had a vision one night that two Babies named Mario and Luigi would cause trouble for Bowser in the future. So he tried to kidnap them. He attacked the stork who was delivering them but missed Baby Mario. Baby Mario landed on Yoshi's back. Yoshi helped save the stork and Baby Luigi from Kamek..
Yoshi's Island DS (Yoshi's Island 2)
Bowser decided to travel back in time to 1984 to steal the stars from the star children so he could conquer the universe. The Yoshi's decide to help Baby Mario, Baby Luigi, Baby Peach, Baby Wario, Baby Waluigi, and Baby Donkey Kong. Even Baby Bowser decides to help defeat his future self.
Mario and Luigi Partners in time (past portion)
In 1985, Princess Shroob ordered an invasion on the Mushroom Kingdom. Mario and Luigi traveled back in time to defeat the Princess Shroob and rescue Princess Peach. After defeating Princess Shroob it was revealed that she had an older twin sister called Elder Princess Shroob who was trapped. Baby Bowser accidentally helped Elder Princess Shroob escape. After Elder Princess Shroob was defeated, her younger brother Prince Shroob took over Planet Shroob
One day in 1991, 12-year old Bowser decided to get revenge on the Yoshi's. He stole the Super Happy Tree and turned Yoshi's Island into a book. It affected the Adult Yoshi's but it did not affect their hatching offspring who decided to go on an adventure to rescue the Super Happy Tree from Bowser and return Yoshi's Island to normal.
Mario vs Donkey Kong
One day in 1997, Mario decided to invent and advertise mini mario toys. Donkey Kong Sr (who is currently known as Cranky Kong) wanted to buy them but they were sold out. So he got angry and kidnapped many mini Mario's as well as 3 Toads (who Mario thought were kids with weird hats. Mario saved the mini Mario's and the toads. After rescuing them Mario scolded DK Sr who felt bad for stealing the mini Mario's. Mario then realized that DK felt guilty so e gave him a mini Mario.
Donkey Kong 3
The next day Donkey Kong later causes trouble in Stanley the Bugman's garden trying to look for a warp pipe back to the Mushroom World. Stanley fights against DK and then tells his cousin Mario about it. Mario gets angry and captures Donkey Kong.
Donkey Kong Circus
After capturing DK Mario decided to make him do circus acts like standing on a barrel and juggling falling objects.
DK Sr was fed up with having to do the circus act so he decided to kidnap Mario's girlfriend Pauline and take her to the top of a construction site. Mario finally saved Pauline.
Donkey Kong Jr
When DK Sr was recaptured, his 13 year old son Donkey Kong Jr decided to rescue his father from Mario. He successfully managed to do that and they escaped back to Donkey Kong Island.
Donkey Kong Game Boy
Donkey Kong Sr and his son decided to kidnap Pauline. Mario however rescued her.
Mario decided to quit being a carpenter in 1998 and decided to get the job Luigi already had. They wrecked stuff.
Wrecking Crew 98
They still wrecked stuff.
Super Mario Brother's Super Show Plumber's Acedemy Backstory
It was August 1st 1999, and the 18-year old Mario brothers were on their first day of college at Plumber's academy. However their professor was Sergeant Kooperman who was really King Koopa in disquise. At that time King Koopa was a criminal in the Mushroom Kingdom planning to overthrow the Toadstool dynasty and conquer the land. He knew of the future plumber heroes of the Mushroom Prophecies that would stop his Koopa Revolution. So he decided to try to Flunk and eliminate the Mario Brothers. But then after flunking and almost drowning, the Mario Brother's saved Bill Clinton and Vladimir Putin from a flood. They were rewarded and Clinton gave Mario the golden plunger. That same day they graduated and became official Plumbers.
Super Mario Brother's Super Show Live Action
From August 2nd 1999 to October 15 1999 the Mario Brothers were plumbers living in Brooklyn where they had stupid Pre-Mushroom Kingdom adventures where they plumbed stuff.
Super Mario Bros Super Show Cartoon Opening Part 1
On October 15 1999 The Mario Brothers were plumbing a tub that they got sucked down into since the pipe widened. They fell down the pipe. Mario and Luigi shouted "SHIIIIIIIIIIIIIIIIT!!!!!!!!!!!!!!" as they were falling down the pipe.
Mario Bros Arcade
The Mario Brother's landed in Brooklyn's sewers after falling down the drain. Koopa Troopa's from the Mushroom world were infesting the sewers because King Koopa wanted to conquer Earth. Mario and Luigi thought "Where are these turtles coming from?" They battled the Koopa's as well as Crabs.